Engineering Commons^™

Design, Fabrication And Applications Of Efficient Conductive Polymers For Photocatalytic Antimicrobials, Chunbo Liu

Electronic Thesis and Dissertation Repository

Designing new antimicrobial surfaces which are effective under visible light irradiation without leaching toxic ions is a current challenge for effective disinfection. A new polymeric system poly[2,11’-thiophene-ethylene-thiophene-alt-2,5-(3-carboxyl) -thiophene] (PTET-T- COOH) with broad light absorption was synthesized. Its photocatalytic disinfection performance against staphylococcus aureus (S. aureus) and streptococcus suis (S. suis) was evaluated, showing over 99.999% inactivation (higher than 5-log inactivation) in 2 h for both bacteria, under visible light irradiation at a low concentration of PTET-T-COOH (0.1 mg/mL). In addition, a PTET-T-COOH/polyurethane (PU) polymeric coating was designed and fabricated. Chemical attachment was confirmed between PTET-T-COOH and PU using various thermophysical …

Photoactive Properties Of Nanostructured Titania Modified Polyurethanes, Chao Chen

Electronic Thesis and Dissertation Repository

In order to enhance both the photoactivity and physical/mechanical properties of titania/polyurethane (PU) nanocomposites, in-situ polymerization and film casting were investigated. Both self-degrading PU foams and self-cleaning PU coatings were prepared. Functional monomers were prepared usingDMPA (2,2-dimethylolpropionic acid) functionalized anatse TiO₂ and P25 for integration into polyurethane foam with a "grafting-from" synthetic method. This technique was found to successfully reduce the agglomeration effect of titania nanoparticles inside the foams. In addition, the photodegradation rate was enhanced by > 120% over unmodified foam at an optimized loading of 3wt% DMPA functionalized anatase TiO₂. The presence of DMPA functionalized P25 …

Antibacterial Studies On Titania Polyurethane Nanocomposite Coatings, Koosha Azhie

Electronic Thesis and Dissertation Repository

While temporary disinfection of a surface is possible with the help of strong cleaners, tremendous interest exists for the control of microorganisms on surfaces by effective, durable antimicrobial coatings. There is a wide spectrum of potential applications for antibacterial coatings, spanning from industrial surface coatings to biomedical applications, where sterile conditions are crucial. This work examined the synthesis of the functionalized 2,2-Dimethylolpropionic acid - nanotitanium dioxide (DMPA-nTiO₂) monomer. Moreover, functionalized nanotitanium dioxide/polyurethane (nTiO₂/PU) composite coatings were prepared using the above mentioned functionalized monomer. The distribution of nTiO₂ in the polymer matrix was enhanced by monomer …

Self-Cleaning Polyurethane And Polyester Coatings, Yixing Tang

Electronic Thesis and Dissertation Repository

Self-cleaning titanium dioxide (TiO₂) based polyurethane and polyester nanocomposites were synthesized, characterized and tested in this thesis. A monomer functionalization method (“grafting from” polymerization) was used for synthesizing both novel nano-TiO₂ coordinated polyurethanes (nano-TiO₂-PU) and nano-TiO₂/polyester nanocomposites. This technique provides the advantage of directly attaching nanoparticles to the polymer backbone.

For polyurethane synthesis, two different methods (one-shot and pre-polymer) were explored. Using several characterization techniques, product from the pre-polymer method showed better mechanical properties; therefore, the pre-polymer method was chosen for subsequent nano-TiO₂-PU synthesis. In the nano-TiO₂-PU synthesis, the …